模拟请求和结果以进行最小的单元测试
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【中文标题】模拟请求和结果以进行最小的单元测试【英文标题】：Mocking request & result to have smallest unit-test possible 【发布时间】：2022-01-14 06:28:45 【问题描述】：我正在使用 Express 构建一个 back-for-front 应用程序。 它通过路由从前面专门调用，然后调用外部 API 来返回结果。这是逻辑的示例代码：
dashboard.route.ts
const router = Router();
const dashboardController = new DashboardController();
router.get("/distantCall", dashboardController.getDistantCall);
dashboard.controller.ts
import Request, Response, NextFunction from "express";
import DashboardService from "../services/dashboard.service";
export class DashboardController
async getDistantCall(req: Request, res: Response, next: NextFunction)
DashboardService.getDistantCalls()
.then((result: any) =>
res.status(200).send(result);
).catch((error: any) =>
next(error);
);
dashboard.service.ts
import DashboardApi from './dashboard.api';
class DashboardService
public async getDistantCall()
return new Promise((resolve, reject) =>
new DashboardApi().getDistantCall()
.then((response: any) =>
resolve(
distantResponse: response.body
);
)
.catch((error) =>
reject(error);
);
);
DashboardAPI 类进行外部 http 调用并返回一个承诺。对于这个示例，它返回一个简单的文本“distantSuccess”
对于我的测试，我可以很容易地编写集成测试
dashboard.routes.spec.ts
import chai from "chai";
import chaiHttp from "chai-http";
import expect from "chai";
chai.use(chaiHttp);
import createServer from "../../src/server";
const app = createServer();
describe("dashboard routes", function()
it('nominal distant call', async () =>
const res = await chai.request(app).get("/dashboard/distantCall");
expect(res.status).to.eq(200);
expect(res.body).to.be.a('object');
expect(res.body).to.have.property('distantResponse');
expect(res.body.distantResponse).to.eq('distantSuccess');
);
);
我的问题是构建 unit 测试。据我了解，我应该只测试控制器或服务，并使用模拟和存根来模拟范围之外的元素。这是我做的两个测试：
dashboard.controller.spec.ts
import Request, Response, NextFunction from "express";
import chai from "chai";
import chaiHttp from "chai-http";
import expect from "chai";
import sinon from "sinon";
chai.use(chaiHttp);
import createServer from "../../src/server";
const app = createServer();
import DashboardController from "../../src/controllers/dashboard.controller";
const dashboardController = new DashboardController();
import DashboardService from "../../src/services/dashboard.service";
describe("dashboard routes with fake objects", function ()
it("distant call by controller", async () =>
const mockRequest: any =
headers: ,
body: ,
;
const mockResponse: any =
body: distantResponse: "About..." ,
text: "test",
status: 200,
;
const mockNext: NextFunction = () => ;
await dashboardController.getDistantCallSucces(mockRequest, mockResponse, mockNext);
expect(mockResponse.status).to.eq(200);
expect(mockResponse.body).to.be.a("object");
expect(mockResponse.body).to.have.property("distantResponse");
expect(mockResponse.body.distantResponse).to.eq("About...");
);
);
describe("dashboard routes with stubs", function ()
before(() =>
sinon
.stub(DashboardService, "getDistantCall")
.yields( distantResponse: "distantSuccess" );
);
it("distant call by controller", async () =>
const mockRequest: any = ;
const mockResponse: any = ;
const mockNext: NextFunction = () => ;
const res = await dashboardController.getDistantCall(mockRequest, mockResponse, mockNext);
console.log(res);
);
);
对于第一次测试，我显然不了解它的用途。我正在测试我刚刚创建的对象，甚至不知道是否调用了该服务。 我觉得我应该做一些更像第二次测试的事情，但我得到了这个错误： TypeError: getDistantCall 预期会产生，但没有通过回调。
【问题讨论】：
【参考方案1】：我终于找到了解决办法。
我创建了两个单独的文件：一个用于集成测试，一个用于单元测试。我稍微调整了来自远程服务器的响应，它现在是 '来自远程服务器'，而不是上一条消息中设置的 "distantResponse"。 在控制器和服务上，我还将 getDistantCall 更改为两个不同的函数 getDistantCallSucces 和 getDistantCallError 以强制解析和拒绝集成测试。
dashboard-integration.spec.ts
import chai, expect from "chai";
import chaiHttp from "chai-http";
chai.use(chaiHttp);
import sinon from "sinon";
import app from "../src/app";
import DashboardAPI from '../src/dashboard/dashboard.api';
describe("Dashboard intagration tests", () =>
describe("Integration with server online", () =>
it('Dashboard routes up', async () =>
const res = await chai.request(app).get("/dashboard");
expect(res.status).to.eq(200);
expect(res.text).to.eq('dashboard');
);
it('full process with expected success', async () =>
const res = await chai.request(app).get("/dashboard/distantCallSuccess").set("code", "12345");
expect(res.status).to.eq(200);
expect(res.body).to.be.a('object');
expect(res.body).to.have.property('distantResponse');
expect(res.body.distantResponse).to.eq('from distant server');
);
it('full process with expected error', async () =>
const res = await chai.request(app).get("/dashboard/distantCallError");
expect(res.status).to.eq(500);
);
);
describe("Integration with mocked server", () =>
beforeEach(() =>
sinon.restore();
);
it('full process with expected resolve', async () =>
const mockedResponse = body: 'mocked';
sinon.stub(DashboardAPI.prototype, 'getDistantCallSuccess').resolves(mockedResponse);
const res = await chai.request(app).get("/dashboard/distantCallSuccess").set("code", "12345");
expect(res.status).to.eq(200);
expect(res.body).to.be.a('object');
expect(res.body).to.have.property('distantResponse');
expect(res.body.distantResponse).to.eq('mocked');
);
it('full process with expected reject', async () =>
sinon.stub(DashboardAPI.prototype, 'getDistantCallSuccess').rejects(mockedError: true);
const res = await chai.request(app).get("/dashboard/distantCallSuccess").set("code", "12345");
expect(res.status).to.eq(500);
);
);
);
dashboard-unit.spec.ts
我不得不使用 node-mocks-http 来模拟请求和响应对象
import chai, expect from "chai";
import chaiHttp from "chai-http";
import sinon from "sinon";
import httpMocks from "node-mocks-http";
chai.use(chaiHttp);
import DashboardController from "../src/dashboard/dashboard.controller";
import DashboardService from "../src/dashboard/dashboard.service";
import DashboardAPI from '../src/dashboard/dashboard.api';
describe("Unit Testing the Dashboard process", () =>
describe("Unit Testing the controller", () =>
const dashboardController = new DashboardController();
beforeEach(() =>
sinon.restore();
);
it("testing controller call without headers [catch]", async () =>
var request = httpMocks.createRequest();
var response = httpMocks.createResponse();
const next = () => ;
await dashboardController.getDistantCallSuccess(request, response, next);
expect(response._getStatusCode()).to.eq(500);
expect(response._getData()).to.eq("Missing HEADER Parameter");
);
it("testing controller call with headers [resolve]", async () =>
const mockedResponse =
mockedResponse: true
;
sinon.stub(DashboardService, 'getDistantCallSuccess').resolves(mockedResponse);
var request = httpMocks.createRequest(
headers: code: "123"
);
var response = httpMocks.createResponse();
const next = () => ;
await dashboardController.getDistantCallSuccess(request, response, next);
expect(response._getStatusCode()).to.eq(200);
expect(response._getData()).to.eql(mockedResponse: true);
);
it("testing controller call with headers [reject]", async () =>
sinon.stub(DashboardService, 'getDistantCallSuccess').rejects(customError: true);
const request = httpMocks.createRequest();
const response = httpMocks.createResponse();
const next = (res) =>
expect(res).to.eql(customError: true);
;
await dashboardController.getDistantCallError(request, response, next);
);
);
describe("Unit Testing the service", () =>
beforeEach(() =>
sinon.restore();
);
it("testing service call with resolve", async() =>
const mockedResponse =
body: 'mocked'
;
sinon.stub(DashboardAPI.prototype, 'getDistantCallSuccess').resolves(mockedResponse);
let result;
await DashboardService.getDistantCallSuccess().then(res =>
result = res;
);
expect(result).to.be.a('object');
expect(result).to.be.haveOwnProperty('distantResponse');
expect(result.distantResponse).to.eq('mocked');
);
it("testing service call with reject", async() =>
sinon.stub(DashboardAPI.prototype, 'getDistantCallSuccess').rejects(mockedError: true);
let result;
await DashboardService.getDistantCallSuccess()
.then(res =>
result = res;
)
.catch(err =>
result = err;
);
expect(result).to.eql(mockedError: true);
);
);
);
【讨论】：
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